# 注册逻辑的序列化器
import re
from django_redis import get_redis_connection
from rest_framework import serializers

from goods.models import SKU
from users import constants
from users.models import User, Address
from celery_tasks.email.tasks import send_verify_email


# 创建用户的序列化器
class CreateUserSerializer(serializers.ModelSerializer):
    """创建用户序列化器"""
    # 添加模型类中没有的字段
    password2 = serializers.CharField(label='确认密码', write_only=True)
    sms_code = serializers.CharField(label='短信验证码', write_only=True)
    allow = serializers.CharField(label='同意协议', write_only=True)
    token = serializers.CharField(label='登录状态token', read_only=True)

    class Meta:
        model = User
        fields = ('id', 'username', 'password', 'password2', 'sms_code', 'mobile', 'allow', 'token')

        # 我们可以使用extra_kwargs参数为ModelSerializer添加或修改原有的选项参数
        extra_kwargs = {
            'username': {
                'min_length': 5,
                'max_length': 20,
                'error_messages': {
                    'min_length': '仅允许5-20个字符的用户名',
                    'max_length': '仅允许5-20个字符的用户名',
                }
            },
            'password': {
                'write_only': True,
                'min_length': 8,
                'max_length': 20,
                'error_messages': {
                    'min_length': '仅允许8-20个字符的密码',
                    'max_length': '仅允许8-20个字符的密码',
                }
            }
        }

    # 添加字段的验证,不能完全相信前端验证
    def validate_mobile(self, value):
        """验证手机号码"""
        if not re.match(r'^1[3-9]\d{9}$', value):
            raise serializers.ValidationError('手机号码格式错误')
        return value

    def validate_allow(self, value):
        """检查用户是否勾选协议"""
        if value != "true":
            raise serializers.ValidationError('请同意用户协议')
        return value

    # 添加字段之间的校验
    def validate(self, attrs):
        # 判断两次密码是否一致
        if attrs['password'] != attrs['password2']:
            raise serializers.ValidationError('两次密码不一致')

        # 判断短信验证码是否正确
        redis_conn = get_redis_connection('verify_codes')
        mobile = attrs['mobile']
        real_sms_code = redis_conn['sms_%s' % mobile]
        if real_sms_code is None:
            raise serializers.ValidationError('无效的短信验证码')
        if attrs['sms_code'] != real_sms_code.decode():
            raise serializers.ValidationError('短信验证码错误')

        return attrs

    # 重写create方法,创建用户,添加密码的加密保存
    # validated_data已经传进来检验好的数据
    def create(self, validated_data):
        """创建用户"""
        # 每次创建对象的时候
        # 移除数据库模型类中不存在的属性
        # 存到数据库中需要移除
        del validated_data['password2']
        del validated_data['sms_code']
        del validated_data['allow']
        # 重新使用父类方法
        user = super().create(validated_data)

        # 调用django的认证系统加密密码
        user.set_password(validated_data['password'])
        user.save()

        # 签发jwt token
        from rest_framework_jwt.settings import api_settings
        jwt_payload_handler = api_settings.JWT_PAYLOAD_HANDLER
        jwt_encode_handler = api_settings.JWT_ENCODE_HANDLER
        payload = jwt_payload_handler(user)
        token = jwt_encode_handler(payload)
        # 临时传递给前端,不会保存到数据库
        user.token = token
        return user


# 用户详情信息序列化器
class UserDetailSerializer(serializers.ModelSerializer):
    """ 展示用户详情的序列化器"""
    class Meta:
        model = User
        fields = ('id', 'username', 'mobile', 'email', 'email_active')
        # 请求放在前端mounted中,加载已完成立马访问视图请求数据


class EmailSerializer(serializers.ModelSerializer):
    """修改邮箱序列化器"""
    class Meta:
        model = User
        fields = ('id', 'email')

    def update(self, instance, validated_data):
        """

        :param instance:  视图传过来的user
        :param validated_data:
        :return:
        """
        email = validated_data['email']
        instance.email = email
        instance.save()
        # 生成激活链接
        url = instance.generate_verify_email_url()
        # 保存的同时发送邮件到异步任务队列
        send_verify_email.delay(email, url)

        return instance


class UserAddressSerializer(serializers.ModelSerializer):
    """
    用户地址序列化器
    """
    province = serializers.StringRelatedField(read_only=True)
    city = serializers.StringRelatedField(read_only=True)
    district = serializers.StringRelatedField(read_only=True)
    province_id = serializers.IntegerField(label='省ID', required=True)
    city_id = serializers.IntegerField(label='市ID', required=True)
    district_id = serializers.IntegerField(label='区ID', required=True)

    class Meta:
        model = Address
        exclude = ('user', 'is_deleted', 'create_time', 'update_time')

    def validate_mobile(self, value):
        """
        验证手机号
        """
        if not re.match(r'^1[3-9]\d{9}$', value):
            raise serializers.ValidationError('手机号格式错误')
        return value

    def create(self, validated_data):
        """
        保存
        """
        validated_data['user'] = self.context['request'].user
        return super().create(validated_data)


class AddressTitleSerializer(serializers.ModelSerializer):
    """
    地址标题
    """
    class Meta:
        model = Address
        fields = ('title',)


class AddUserBrowsingHistorySerializer(serializers.Serializer):
    """
    添加用户浏览历史序列化器
    """
    sku_id = serializers.IntegerField(label="商品SKU编号", min_value=1)

    def validate_sku_id(self, value):
        """
        检验sku_id是否存在
        """
        try:
            SKU.objects.get(id=value)
        except SKU.DoesNotExist:
            raise serializers.ValidationError('该商品不存在')
        return value

    def create(self, validated_data):
        """
        保存
        """
        user_id = self.context['request'].user.id
        sku_id = validated_data['sku_id']

        redis_conn = get_redis_connection("history")
        pl = redis_conn.pipeline()

        # 移除已经存在的本商品浏览记录
        pl.lrem("history_%s" % user_id, 0, sku_id)
        # 添加新的浏览记录
        pl.lpush("history_%s" % user_id, sku_id)
        # 只保存最多5条记录
        pl.ltrim("history_%s" % user_id, 0, constants.USER_BROWSING_HISTORY_COUNTS_LIMIT-1)

        pl.execute()

        return validated_data


class SKUSerializer(serializers.ModelSerializer):
    class Meta:
        model = SKU
        fields = ('id', 'name', 'price', 'default_image_url', 'comments')
